Bug 837267 - [Browser] The URL bar treats any string containing a period as a URL

...ect error

Based on a robust URL validation expression by Diego Perini, execute more specific checks on the input before proceeding as either a search term or a URL.

https://bugzilla.mozilla.org/show_bug.cgi?id=837267

Signed-off-by: Rick Waldron <waldron.rick@gmail.com>